Cyanogen-containing electroplating wastewater treatment process

Abstract

The invention provides a cyanogen-containing electroplating wastewater treatment process. The cyanogen-containing electroplating wastewater treatment process comprises the following steps that 1, the cyanogen-containing electroplating wastewater is fed into an electrolytic cell to be subjected to electrolytic cyanogen removal treatment; 2, the cyanogen-containing electroplating wastewater subjected to electrolytic cyanogen removal treatment in the electrolytic cell is fed into a wastewater reaction tank, sodium hypochlorite is added to oxidize cyanide ions in the cyanogen-containing electroplating wastewater into cyanogen chloride; 3, NaOH is added into the wastewater reaction tank, the cyanogen chloride produced in the step 2 is converted into sodium cyanate; 4, industrial dilute sulfuric acid is added into the wastewater reaction tank, the pH value of the wastewater is regulated to be 7-8; 5, sodium hypochlorite is added into the wastewater reaction tank again to convert the sodium cyanate generated in the step 3 into NaOH and NaCl; 6, the wastewater treated through the step 5 is fed into a sedimentation tank, and a flocculating agent is added into the sedimentation tank. The cyanogen-containing electroplating wastewater treatment process is simple in treatment mode, the electrolytic time is short, the content of the cyanide ions in the treated wastewater is low, and the A-level standard of Integrated Wastewater Discharge Standard (GB8978-1996) is met.

Description

technical field [0001] The invention relates to a process for treating cyanide-containing electroplating wastewater. Background technique [0002] Cyanide-containing wastewater is mainly produced in rare metal smelting and electroplating production. Among the many types of plating, cyanide plating is one of the commonly used plating types, mainly used for zinc plating, lead plating, cadmium plating, copper plating, silver plating, and gold plating. In cyanide-containing wastewater, in addition to highly toxic free cyanide, there are complex ions such as copper cyanide, cadmium cyanide, silver cyanide, and zinc cyanide. CN in wastewater - The mass concentration is high, and it also contains a large amount of heavy metals, thiocyanate and other compounds, which seriously pollute the external water environment. Cyanide is a highly toxic substance, CN - It will combine with ferricytochrome enzyme in the human body to generate cyanide ferricytochrome oxidase and lose the oxyg...

AI Technical Summary

Problems solved by technology

However, the patent proposes a process for treating cyanide- and chromium-containing wastewater at the same time, which is not highly targeted. Generally, electroplating waste liquid basically does not contain both cyanide and chromium pollution ions at the same time. Therefore, its applicability is not strong. Increased processing costs